Tray table trays

ABSTRACT

Trays for tray tables that prevent liquid spilled on a top surface of the trays from spreading over edges of the trays. A casing having a top surface with at least one aperture through the top surface, a receptacle within the casing positioned below the aperture in the top surface configured to receive an absorbent pad that can be removably positioned in the receptacle below the aperture to be in communication with the top surface of the tray. Spilled liquids can be guided toward the aperture in the top surface and absorbed in the absorbent pad within the casing. The absorbent pad may be a superabsorbent material. The top surface can have a superhydrophobic coating.

TECHNICAL FIELD

This disclosure relates generally to portable tables and, moreparticularly, to trays for use in tray tables that prevent liquidsspilled on a top surface of the tray from spreading over the edges ofthe top surface and provide for easy cleanup.

BACKGROUND

Tray tables generally consist of a tray mounted on folding legs or atray mounted on or in a piece of furniture, such as an airplane or trainseatback, and designed to fold or swing out of the way for storage. Forexample, a tray table may be stowed flat against an airplane seatbackand readily folded down to a generally horizontal usable position toprovide a surface upon which a passenger can place a drink and/or eat ameal. Such trays are typically affixed to the seatback by a pair of armsthat are pivotally attached to the seatback and to the tray, and oftenhave a top surface with recessed areas therein where glasses, bottles,cups or cans can be placed. The recessed areas reduce the risk ofknocking over the glasses, bottles, cups or cans, but they do notprevent liquid from spreading over the tray's top surface or over theedges of the tray once a liquid has been spilled.

It is common, particularly in airplanes, trains and other vehicles, fordrinks resting on a tray table surface to be spilled for various reasonssuch as vibration resulting from vehicle movement, severe turbulencesand passenger inadvertence. Tray table trays are typically made from alightweight plastic-type material or other materials that arehydrophobic. Spilled liquids can freely spread over the tray surface anddrip over the edges of the tray, dirtying the vehicle interior and thepassenger's clothing. This can influence passenger satisfaction, andrequires that the spill be cleaned up prior to the next departure forthe vehicle. For liquids that are difficult remove, such as red wine,additional time and cleaning supplies may be necessary.

SUMMARY

In accordance with some aspects of this disclosure, the tray comprises acasing having a top surface with at least one aperture through the topsurface and a receptacle within the casing positioned below the aperturein the top surface. The receptacle is configured to receive an absorbentpad, which can be removably positioned in the receptacle below theaperture to be in communication with the top surface, such that liquidspilled on the top surface can flow through the aperture and into theabsorbent pad. The absorbent pad can be a superabsorbent material thatcan absorb and retain large amounts of a liquid relative to its own massso that it quickly absorbs any spilled liquid on the top surface of thetray and reduces the frequency of having to replace the absorbentmaterial. A superhydrophobic coating can be applied on the top surfaceof the casing to provide a high degree of liquid repellency. Thegeometry of the top surface can be configured to guide any liquidspilled on the tray toward the aperture through the top surface and intothe absorbent pad.

In accordance with one aspect of the disclosure, the top surfacecomprises three elongated apertures positioned proximate three sides (arear side, a left side and a right side) of the casing. The top surfaceof the casing can be generally flat and may have a raised edge at afront side of the casing that forms a barrier to prevent a liquidspilled on the top surface from dripping over the raised edge and toguide the liquid toward the elongated apertures in the rear side, theleft side and the right side of the casing.

In accordance with another aspect of the disclosure, the top surfacecomprises at least one sloped portion that is sloped down toward andterminates at the aperture through the top surface. The sloped portioncan guide a liquid spilled on the top surface toward the aperture andinto the absorbent pad. The slope of the sloped portion can be slight,just enough to provide the guiding function without causing objectsplaced on the sloped portion to fall over. For example, the top surfacemay have a single elongated aperture extending generally parallel to,and positioned proximate, a rear side of the casing, such that theelongated aperture extends a substantial part of the width of the rearside. The sloped portion of the top surface may have a width at least aswide as the width of the elongated aperture and the slope of the slopedportion may cause the front side of the top surface to be at a higherlevel than the rear side of the top surface. The top surface can includea first raised edge at a left side of the casing and a second raisededge at right side of the casing to form a barrier to prevent a liquidspilled on the top surface from dripping over the left side and theright side of the casing and to further guide the liquid toward theelongated aperture.

In another example, the aperture is positioned proximate a center of thetop surface and the top surface comprising four slopes extending fromthe right side, left side, rear side and front side of the casing downtoward the aperture in the center of the top surface. The slope of thesloped portions can cause the center of the top surface to be at a lowerlevel than all of the sides of the top surface, and permit the apertureto act as a central drain.

In yet other aspects of the disclosure, a method for manufacturing atray for tray table that can prevent a liquid spilled on a top surfaceof the tray from spreading over an edge of the tray is provided. Themethod includes the steps of forming a casing having a receptacle withinthe casing and a top surface with at least one aperture through the topsurface in communication with the receptacle, such that during use aremovable absorbent pad can be inserted in the receptacle below theaperture and in communication with the top surface. The absorbent padcan be a superabsorbent material that can absorb and retain largeamounts of a liquid relative to its own mass so that it quickly absorbsany spilled liquid on the top surface of the tray and reduces thefrequency of having to replace the absorbent material. The step offorming the casing can include forming an opening through a side of thecasing in communication with the receptacle, such that the removableabsorbent pad may be inserted and removed from the receptacle throughthe opening, applying a superhydrophobic coating on the top surface ofthe casing to provide a high degree of liquid repellency, andconfiguring the top surface to guide any liquid spilled on the traytoward the aperture through the top surface and into the absorbent pad.

The features, functions and advantages that have been discussed, as wellas other objects, features, functions and advantages of the tray can beachieved independently in various examples of the disclosure or may becombined in yet other examples, further details of which can be seenwith reference to the following description and drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram representing a top view of a tray for a tray tablein accordance with some aspects of this disclosure.

FIG. 2 is a diagram representing a left side view of the tray shown inFIG. 1.

FIG. 3 is a diagram representing a cross-sectional view of the traytaken along the line 3-3 in FIG. 1.

FIG. 4 is a diagram representing a cross-sectional view of the traytaken along the line 4-4 in FIG. 1.

FIG. 5 is a diagram representing a top view of a tray for a tray tablein accordance with other aspects of this disclosure.

FIG. 6 is a diagram representing a left side view of the tray shown inFIG. 5.

FIG. 7 is a diagram representing a cross-sectional view of the traytaken along the line 7-7 in FIG. 5.

FIG. 8 is a diagram representing a cross-sectional view of the traytaken along the line 8-8 in FIG. 5.

FIG. 9 is a diagram representing a top view of a tray for a tray tablein accordance with still other aspects of this disclosure.

FIG. 10 is a diagram representing a left side view of the tray shown inFIG. 9.

FIG. 11 is a diagram representing a cross-sectional view of the traytaken along the line 11-11 in FIG. 9.

FIG. 12 is a diagram representing a cross-sectional view of the traytaken along the line 12-12 in FIG. 9.

FIG. 13 is a diagram representing a bottom view of the trays shown inany of FIGS. 1-12.

FIG. 14 is a flow chart of a method of manufacturing a tray for a traytable.

DETAILED DESCRIPTION

The trays described herein can prevent spilled liquids from spreadingoutside the tray surface and provide for quick and easy clean-up. Theforegoing benefit as well as others, are achieved by a tray for a traytable that collects liquid spilled on a top surface of the tray in areplaceable absorbent pad positioned in a receptacle within the tray,and therefore reduces the risk of spilled liquid spreading over edges ofthe tray and dirtying the surrounding area and user of the tray table.The replaceable pad is easily inserted into and removed from thereceptacle in the tray, and can include an indicator for indicating whenthe absorbent pad has reached maximum capacity and requires replacement.

In the following detailed description and the drawing figures,illustrative embodiments of a tray 10 for a tray table and methods forpreventing a liquid spilled on a top surface 12 of a tray 10 fromspreading over an edge 14 of the tray 10 are described. The descriptionis merely exemplary in nature and is not intended to limit the disclosedtray or the application and uses of the disclosed tray. It will berecognized by one skilled in the art that the present disclosure may bepracticed in a variety of applications or environments and/or with otheranalogous or equivalent variations of the illustrative examples. Forexample, the concepts and teachings disclosed herein may be applied to atray of the type used with tray tables on seatbacks in aircraft, trainsand other vehicles, or any other type of portable table or surface uponwhich a liquid could spill.

It should be noted that those methods, procedures, components, orfunctions which are commonly known to persons of ordinary skill in thefield of the disclosure are not described in detail herein. A personskilled in the art will appreciate that in the development of an actualembodiment, numerous implementation-specific decisions must be made toachieve the developer's specific goals, which will vary from oneimplementation to another. Moreover, it will be appreciated that such adevelopment effort might be complex and time-consuming, but wouldnevertheless be a routine undertaking for those of ordinary skill in theart having the benefit of this disclosure.

Referring to the drawings, the tray 10 comprises a casing 16 having atop surface 12 with at least one aperture 18 through the top surface 12.The aperture 18 acts as a drain for liquid that is spilled on the topsurface 12. The aperture 18 may take any form including, withoutlimitation, a round, square or rectangular shaped hole or slot. Theaperture 18 need not be covered, but may have a pervious or mesh coverplaced over the aperture 18. The casing 16 may be made from any type oflightweight, moldable and sturdy material, such as aluminum, metal orplastic, and formed into a shape suitable for a particular use. Forexample, the tray 10 may have a generally rectangular shape and be usedin a tray table that is pivotably and foldably attached to a seatback inan airplane or train, such that the tray table can be selectively foldeddown by a passenger seated in the immediately rearward seat.

Referring more particularly to FIGS. 2-4, 6-8 and 10-12, a receptacle 20is positioned within the casing 16 and below the aperture 18 in the topsurface 12, and configured to receive an absorbent pad 22 that can beremovably positioned in the receptacle 20 below the aperture 18 to be incommunication with the top surface 12. The absorbent pad 22 isconfigured to absorb liquid that spills on the top surface 12 and entersthe aperture 18. The receptacle 20 extends under substantially an entirearea 13 of the top surface 12, and the absorbent pad 22 substantiallyfills the receptacle 20 such that the absorbent pad 22 fills betweenabout 25% to 80% of the volume of the receptacle 20. The casing 16 hasan opening 24 in a side 26 of the casing 16 in communication with thereceptacle 20 that permits insertion and removal of the absorbent pad 22into and out of the receptacle 20. As shown in FIGS. 2 and 6, a lockingdevice 28 may optionally be included for maintaining the absorbent pad22 in the receptacle 20. For example, a pivotable bar 30 may bepositioned on the side 26 of the casing 16 to rotate about a pivot point32 positioned above or below the opening 24, such that the pivotable bar30 is moveable between a horizontal position that permits entry of theabsorbent pad 22 and a vertical position that blocks the opening 24 andprevents the absorbent pad 22 from being removed.

In use, it is desirable to use an absorbent pad 22 that does not requirefrequent replacement, and can be used until the absorbent pad 22 reachesits maximum capacity without leaking. An absorbent pad 22 comprising asuperabsorbent material, such as a superabsorbent polymer (SAP) that canabsorb and retain extremely large amounts of a liquid relative to itsown mass, meets those goals. For example, in a 0.9% saline solution, aSAP may absorb about 50 times its weight, and in deionized and distilledwater, a SAP may absorb about 300 times its weight. Superabsorbentpolymer (SAP) is made from the polymerization of acrylic acid blendedwith sodium hydroxide in the presence of an initiator to form apoly-acrylic acid sodium salt (sometimes referred to as sodiumpolyacrylate). Commercial products based on SAP materials are oftenreferred to as slush powder. Superabsorbent polymers also act as smellabsorbers, which will prevent odors from the liquid absorbed thereinfrom permeating from the SAP, and therefore extend the life of the SAPbefore replacement. Alternatively, an absorbent, but not superabsorbent,silica gel—a SiO₂ based polymer—may be used instead of the SAP.

The state of the absorbent pad 22 may be checked visually or by touch bysliding the absorbent pad 22 out of the receptacle 20. Alternatively, avisual indicator may be provided to assess the amount of liquid absorbedin the absorbent pad 22 and indicate when the absorbent pad 22 hasreached its maximum capacity and should be replaced. For example, apiece of material that dissolves in water-based liquids may bepositioned at a point that is located in the furthermost spot from theaperture 18. SAP material or Silica gel may be doped with a moistureindicator that gradually changes its color when it transitions from theanhydrous (dry) state to the hydrated (wet) state. Common indicators arecobalt chloride and methyl violet. Digital humidity meters may also belocated in at least three different locations inside the absorber, andthe measurements can be combined and presented on the visible side ofabsorber, for example with LEDs or a simple LCD display. All suchindicators may be checked either by sliding the absorbent pad 22 out ofthe receptacle 20 or through an optional window 34 through a bottom 36of the casing 16, as shown in FIG. 13, positioned below the absorbentpad 22. The window 34 is covered with a clear plastic or glass covering38 that permits visual inspection of the absorbent pad 22.

It is also desirable to provide a top surface 12 of the casing 16 thatrepels a liquid spilled on the top surface 12 (and prevents the liquidfrom permeating into the top surface 12) to assist the liquid's movementtoward the aperture 18 and into the absorbent pad 22. One way to providesuch a surface is to coat a superhydrophobic coating 40 on the topsurface 12 of the casing 16 such that the superhydrophobic coating 40becomes a part of the top surface 12. A superhydrophobic coating 40 is ananoscopic surface layer that repels liquids. Droplets hitting thesuperhydrophobic coating 40 can fully rebound in the shape of a columnor pancake and glide across the superhydrophobic coating 40. Theproperty that is used for characterizing hydrophobicity of a material isthe contact angle between a liquid droplet and the surface of material.Superhydrophobicity is achieved when the contact angle is above 150degrees. The top surface 12 of the casing 16 should therefore have acontact angle between a liquid droplet and the top surface 12 greaterthan 150 degrees. Materials suitable for providing the superhydrophobiccoating 40 are based on nano-composites like manganese oxidepolystyrene, zinc oxide polystyrene, or silica nanoparticles. Examplesof commercially-available materials suitable for the superhydrophobiccoating 40 include, but are not limited to, NEVERWET® coatings availablefrom NeverWet, LLC of Lancaster, Pa., superhydrophobic materialsavailable from Aculon, Inc. of San Diego, Calif., and ULTRA EVER DRY®available from UltraTech International, Inc. of Jacksonville, Fla.

The geometry of the top surface 12 of the casing 16 can be arranged inmany different configurations to achieve the desired result of guiding aspilled liquid toward the at least one aperture 18 in the top surfacesuch that the liquid is absorbed into the absorbent pad 22 positioned inthe receptacle 20. FIGS. 1-4 show a first example of a surface geometry,wherein the top surface 12 comprises three elongated apertures 42. Theelongated apertures 42 extend linearly generally parallel to, and arepositioned proximate to, a rear side 44, a left side 46 and a right side48 of the casing 16. The elongated apertures 42 have a width of about3-6 mm to limit the capillary effect that could block liquid fromefficiently moving through the aperture 18 to the absorbent pad 22, butother widths may be employed for different tray 10 designs. In thisexample, the top surface 12 of the casing 16 is generally flat and has araised edge 50 at a front side 52 of the casing 16 that forms a barrierto prevent a liquid spilled on the top surface 12 from dripping over theraised edge 50. The raised edge 50 also serves to guide the liquidtoward the elongated apertures 42 in the rear side 44, the left side 46and the right side 48 of the casing 16. The raised edge 50 has an angleA relative to the plane B of the top surface 12 up to 90 degrees, andpreferably greater than 30 degrees. Although not shown in this example,the top surface 12 may also include one or more sloped portions having aslope of about 0.5 to 1.0 degree that are sloped down toward theelongated apertures 42. The sloped portions provide a direction for aliquid to move along the top surface 12, and may be used to reduce thenumber of apertures 18 or the size of the apertures 18.

In other examples, the top surface 12 of the casing 16 has at least onesloped portion 54 sloped down toward and terminating at the aperture 18through the top surface 12. The slope S of the sloped portion 54 isslight, just enough to provide the guiding function without causingobjects placed on the sloped portion to fall over, for example, thesloped portion 54 has a slope S of about 0.5 to 1.0 degree relative to ahorizontal plane 56 of the casing 16. FIGS. 5-8 show a tray 10 having atop surface 12 with a sloped portion 54 that is sloped from the frontside 52 of the casing 16 down toward the rear side 44 of the casing;that is the slope S of the sloped portion 54 causes the front side 52 ofthe top surface 12 to be at a higher level than the rear side 44 of thetop surface 12. The sloped portion 54 terminates at the aperture 18through the top surface 12, which is configured in this example as asingle elongated aperture 42 extending linearly generally parallel to,and positioned proximate to, the rear side 44 of the casing 16, suchthat the elongated aperture 42 extends a substantial part of the widthof the rear side 44. The slope S of the sloped portion 54 guides aliquid spilled on the top surface 12 toward the aperture 18 and into theabsorbent pad 22. The sloped portion 54 has a width at least as wide asthe width of the elongated aperture 42. In this example, the top surface12 of the casing 16 includes a first raised edge 50 a at a left side 46of the casing 16 and a second raised edge 50 b at a right side 48 of thecasing 16 to form a barrier to prevent a liquid spilled on the topsurface 12 from dripping over the left side 46 and the right side 48 ofthe casing 16 and to further guide the liquid toward the elongatedaperture 42.

FIGS. 9-12 show another example of a tray 10 having sloped portions 54in the top surface 12 of the casing 16. In this example, the aperture 18is configured as a round hole that is positioned proximate a center 58of the top surface 12. The hole in the center 58 need not be round; itcould be square, rectangular or any other shape. The top surface 12 hasfour sloped portions 54 extending from a right side 48, a left side 46,a rear side 44 and a front side 52 of the casing 16 that all slopedownward toward the aperture 18 in the center 58 of the top surface 12.The sloped portions 54 have a slope of about 0.5 to 1.0 degrees thatcauses the center 58 of the top surface 12 to be at a lower level thanall of the sides of the top surface 12, and permits the aperture 18 toact as a central drain. The features described with respect to FIGS.1-4, FIGS. 5-8, FIGS. 9-12, and FIG. 13 can be combined in any number ofways that prevent a liquid from flowing over an edge of the tray 10and/or to channel the liquid to the absorbent pad 22 within the casing16.

Referring to FIG. 14, a method 100 for making a tray 10 for a tray tableas shown in FIGS. 1-13 that can prevent a liquid spilled on a topsurface 12 of the tray 10 from spreading over an edge 14 of the tray 10is provided. In step 102, a casing 16 is formed having a receptacle 20within the casing 16 and a top surface 12 with at least one aperture 18through the top surface 12 in communication with the receptacle 20. Instep 104, during use, a removable absorbent pad 22 is inserted into thereceptacle 20 below the aperture 18 to be in communication with the topsurface 12. As disclosed above, in step 106, the absorbent pad 22 can bea superabsorbent material that can absorb and retain large amounts of aliquid relative to its own mass so that it quickly absorbs any spilledliquid on the top surface 12 of the tray 10 and reduces the frequency ofhaving to replace the absorbent pad 22. In step 108, a superhydrophobiccoating 40 can be coated on the top surface 12 of the casing 16 toprovide a high degree of liquid repellency. In step 110, the top surface12 can be configured to guide any liquid spilled on the tray 10 towardthe aperture 18 through the top surface 12 and into the absorbent pad22.

While the tray 10 has been described with reference to variousembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the teachings herein. Forexample, and without limitation, the shape of the tray 10, the area ofthe top surface 13, the angle A of the raised edge 50, and otherelements may be adjusted to accommodate other design considerations. Thetray 10 may be manufactured and sold with or without the absorbent pad.In addition, many modifications may be made to adapt the concepts andreductions to practice disclosed herein to a particular situation.Accordingly, it is intended that all such modifications and variationsbe considered as within the spirit and scope of this disclosure, asdefined in the following claims, and that the subject matter covered bythe claims not be limited the disclosed embodiments. The process claimsset forth hereinafter should not be construed to require that the stepsrecited therein be performed in the order in which they are recited orin alphabetical order (any alphabetical ordering in the claims is usedsolely for the purpose of referencing previously recited steps).

The invention claimed is:
 1. A tray for a tray table that is pivotablyattached to a seatback and movable between a stowed position and agenerally horizontal usable position, the tray comprising: a casinghaving a top surface with at least one aperture through the top surface,a bottom surface, and side surfaces surrounding the casing andconnecting the top surface to the bottom surface, the top surface of thecasing providing a usable table surface when the tray table is movedinto the generally horizontal usable position; a receptacle within thecasing positioned below the aperture in the top surface of the casing;and an absorbent pad positioned within the receptacle below the apertureand in communication with the top surface through the aperture in thetop surface of the casing; and an opening through one of the sidesurfaces of the casing that permits insertion and removal of theabsorbent pad into and out of the receptacle through the opening.
 2. Thetray according to claim 1, wherein the absorbent pad comprises asuperabsorbent material doped with a moisture indicator that changescolor when it transitions from a dry state to a wet state.
 3. The trayaccording to claim 2, further comprising a superhydrophobic coating onthe top surface of the casing that provides the top surface with acontact angle between a liquid droplet and the top surface greater than150 degrees.
 4. The tray according to claim 1, further comprising a apivotable bar positioned proximate the opening in the casing andmoveable between a horizontal position that permits entry of theabsorbent pad through the opening and a vertical position that blocksthe opening and prevents the absorbent pad from being removed.
 5. Thetray according to claim 1, wherein the receptacle extends undersubstantially an entire area of the top surface, and the absorbent padsubstantially fills the receptacle.
 6. The tray according to claim 2,further comprising a window through a bottom of the casing positionedbelow the absorbent pad that permits visual inspection of the moistureindicator in the absorbent pad without having to remove the absorbentpad from the receptacle.
 7. The tray according to claim 3, wherein thetop surface comprises three elongated apertures, the elongated aperturespositioned proximate a rear side, a left side and a right side of thecasing.
 8. The tray according to claim 7, wherein the top surfacefurther comprises a raised edge at a front side of the casing that formsa barrier to prevent a liquid spilled on the top surface from drippingover the raised edge and to guide the liquid toward the elongatedapertures in the rear side, the left side and the right side.
 9. Thetray according to claim 3, wherein the top surface comprises at leastone sloped portion sloped down toward and terminating at the aperturethrough the top surface.
 10. The tray according to claim 9, wherein thesloped portion has a slope of about 0.5 to 1.0 degree.
 11. The trayaccording to claim 9, wherein the top surface comprises an elongatedaperture extending generally parallel to, and positioned proximate, arear side of the casing.
 12. The tray according to claim 11, wherein thetop surface further comprises a first raised edge at a left side of thecasing and a second raised edge at a right side of the casing that forma barrier to prevent a liquid spilled on the top surface from drippingover the left side and the right side of the casing and to guide theliquid toward the elongated aperture.
 13. The tray according to claim 9,wherein the aperture is positioned proximate a center of the topsurface, the top surface comprising four slopes extending from a rightside, a left side, a rear side and a front side of the casing downtoward the aperture in the center of the top surface.
 14. method formaking a tray for a tray table that is pivotably attached to a seatbackand movable between a stowed position and a generally horizontal usableposition, the method comprising the step of: forming a casing having areceptacle within the casing, a top surface with at least one aperturethrough the top surface in communication with the receptacle, a bottomsurface, side surfaces surrounding the casing and connecting the topsurface to the bottom surface, and an opening through one of the sidesurfaces that permits insertion and removal of an absorbent pad, the topsurface providing a usable table surface when the tray is moved into thegenerally horizontal usable position; and inserting the absorbent padthrough the opening in one of the side surfaces of the casing andpositioning the absorbent pad within the receptacle below the apertureto be in communication with the top surface.
 15. The method of claim 14,further comprising forming the absorbent pad from a superabsorbentmaterial doped with a moisture indicator that changes color when ittransitions from a dry state to a wet state.
 16. The method of claim 15,further comprising coating the top surface of the casing with asuperhydrophobic coating to provide the top surface with a contact anglebetween a liquid droplet and the top surface greater than 150degrees.17. The method of claim 14, wherein the step of forming the casingfurther comprises providing a pivotable bar proximate the opening andmoveable between a horizontal position that permits entry of theabsorbent pad through the opening in one of the side surfaces and avertical position for maintaining the absorbent pad in the receptacle.18. The method of claim 14, wherein the step of forming the casingfurther comprises forming the top surface with at least one slopedportion sloped down toward and terminating at the aperture through thetop surface.
 19. The method of claim 14, further comprising the step ofextending the receptacle under substantially an entire area of the topsurface.
 20. The method of claim 15, further comprising the step ofpositioning a window through a bottom of the casing below the absorbentpad to permit visual inspection of the moisture indicator in theabsorbent pad without having to remove the absorbent pad from thereceptacle.